Jackson Estuarine Laboratory

Photosynthetic studies of Chondrus crispus


The net photosynthesis of intertidal, subtidal, carposporic, tetrasporic, and winter versus summer acclimatized plants of Chondrus crispus Stackhouse were evaluated under different temperatures and quantities of light. The optimum temperature and light conditions for net photosynthesis of C. crispus are seasonally and spatially variable, and there is an adaptive shift in the photosynthetic capacity at different seasons and positions on the shore. Plants collected during the fall and winter had lower light optima (465 to 747 ft-c) for net photosynthesis than spring and summer specimens (about 1000 ft-c). Intertidal populations exhibited a higher rate of net photosynthesis between 250 and 2819 ft-c than subtidal plants. Summer materials have a greater tolerance to high temperatures and a higher temperature optimum than winter materials. Shallow subtidal populations (-6m) exhibited a higher temperature optimum than deep subtidal plants (-12m). Tetrasporic plants (diploid) showed a higher rate of net photosynthesis than carposporic plants (haploid). It is suggested that the diploid plants of C. crispus may extend deeper in the subtidal zone, because they have a higher rate of net photosynthesis than carposporic plants. The results of the present studies are compared with previous physiological studies of C. crispus.

Publication Date


Journal Title

Marine Biology

Digital Object Identifier (DOI)

Document Type



Copyright © 1975, Springer Nature